A former Omaha teacher has been sentenced to 40 years in prison for having a sexual relationship with a former student of his.

Online court records say 36-year-old Brian Robeson was sentenced Tuesday. He'd made a deal with prosecutors and pleaded guilty to sexual assault of a minor. Prosecutors had lowered the charge and dropped another in exchange for Robeson's plea.

Robeson was a math teacher at Davis Middle School. Authorities say the relationship began when the girl was 13.